org.apache.sis.measure

Class Latitude

Object

Angle

Latitude

All Implemented Interfaces:

Serializable, Comparable<Angle>, Formattable

public final class Latitude
extends Angle

A latitude angle in decimal degrees. Positive latitudes are North, while negative latitudes are South. The latitude symbol is the Greek lower-case letter phi (φ).

Because the Earth is not a perfect sphere, there is small differences in the latitude values of a point depending on how the latitude is defined:

• Geodetic latitude is the angle between the equatorial plane and a line perpendicular to the ellipsoid surface.
• Geocentric latitude is the angle between the equatorial plane and a line going from the Earth center. It differs from geodetic latitude by less than 11 angular minutes.
• Astronomical latitude is the angle between the equatorial plane and a line given by the direction of a plumb line (the "true vertical").
• Above list is not exhaustive. There is also geomagnetic latitude, etc.

The kind of latitude is unspecified by this Latitude class, and rather depends on the context: the latitude is geodetic if the coordinate reference system is geographic, or geocentric if the coordinate reference system is geocentric. If the context is unknown, then geodetic latitude can usually be assumed.

Immutability and thread safety

This final class is immutable and thus inherently thread-safe.

Since:

0.3

See Also:

Longitude, Angle­Format, Serialized Form

Defined in the sis-utility module

Field Summary

Fields

Modifier and Type	Field and Description
static double	MAX_VALUE Maximum usual value for latitude (+90.0°).
static double	MIN_VALUE Minimum usual value for latitude (-90.0°).

Constructor Summary

Constructors

Constructor and Description
Latitude(double φ) Construct a new latitude with the specified angular value.
Latitude(String string) Constructs a newly allocated Latitude object that contain the angular value represented by the string.

Method Summary

Modifier and Type	Method and Description
static double	clamp(double φ) Returns the given latitude value clamped to the [-90 … 90]° range.

Methods inherited from class Angle

compare­To, degrees, equals, format­To, hash­Code, radians, to­String

Methods inherited from class Object

clone, finalize, get­Class, notify, notify­All, wait, wait, wait

Field Detail

MIN_VALUE

public static final double MIN_VALUE

Minimum usual value for latitude (-90.0°).

See Also:

Default­Coordinate­System­Axis.get­Minimum­Value(), Constant Field Values

MAX_VALUE

public static final double MAX_VALUE

Maximum usual value for latitude (+90.0°).

See Also:

Default­Coordinate­System­Axis.get­Maximum­Value(), Constant Field Values

Constructor Detail

Latitude

public Latitude(double φ)

Construct a new latitude with the specified angular value.

Parameters:

φ - Latitude value in decimal degrees.

Latitude

public Latitude(String string)
         throws NumberFormatException

Constructs a newly allocated Latitude object that contain the angular value represented by the string. The string should represent an angle in either fractional degrees (e.g. 45.5°) or degrees with minutes and seconds (e.g. 45°30'). The hemisphere (N or S) is optional (default to North).

This is a convenience constructor mostly for testing purpose, since it uses a fixed locale. Developers should consider using Angle­Format for end-user applications instead than this constructor.

Parameters:

string - A string to be converted to a Latitude.

Throws:

Number­Format­Exception - if the string does not contain a parsable angle, or represents a longitude angle.

See Also:

Angle­Format.parse(String)

Method Detail

clamp

public static double clamp(double φ)

Returns the given latitude value clamped to the [-90 … 90]° range. If the given value is outside the latitude range, then this method replaces it by ±90° with the same sign than the given φ value.

Special cases:

• NaN values are returned unchanged
• ±∞ are mapped to ±90° (with the same sign)
• ±0 are returned unchanged (i.e. the sign of negative and positive zero is preserved)

Parameters:

φ - The latitude value in decimal degrees.

Returns:

The given value clamped to the [-90 … 90]° range, or NaN if the given value was NaN.

Since:

0.4

See Also:

Longitude.normalize(double)